Sulfur adsorption on the goethite (110) surface

S. SIMONETTI; D. DAMIANI; G. BRIZUELA; A. JUAN

Surface Review and Letters

Año: 2006 vol. 13 p. 1 - 9

The electronic structure of S adsorption on goethite (110) surface has been studied by ASEDMO cluster calculations. For S location, the most exposed surface atoms of goethite surface were selected. The calculations show that the surface offers several places for S adsorption. The most energetically stable system corresponds to S location above H atom. We studied in detail the configurations that correspond to the higher OP values. For these configurations, the H-S and Fe-S computed distances are, respectively 2.1 and 3.7 Å. The H-S and Fe-S are mainly bonding interaction with OP values of 0.156 and 0.034, respectively. The Fe-S interaction mainly involves Fe 3dx2-y2 atomic orbitals with lesser participation of Fe 4py and Fe 3dyz atomic orbitals. The O-S interaction shows the same bonding and antibonding contributions giving a small OP value. The O-S interaction involves O 2p orbitals. There is an electron transfer to the Fe atom from the S atom. On the other hand, there is an electron transfer to S atom from the H and O atoms, respectively.